Re: [PATCH V2 0/6][RFC] futex: FUTEX_LOCK with optional adaptive spinning

[Ulrich Drepper]

On Sat, Apr 10, 2010 at 16:35, Alan Cox <alan@xxxxxxxxxxxxxxxxxxx> wrote:
> You only need one page per 4096 threads

Very expensive.  Each cache line would be fought over by 64 threads.
Constant RFOs make context switches significantly slower.

At most 4096/64 = 64 threads should share one page.  One page would
still cover almost all processes.
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